Process for the manufacture of artificial silk and other products from cellulose esters



\ Patented Sept 1, 1925.

nuns BINDSCHEDLER, or PHILADELPHIA, PENNSYLVANIL'AND GEORGE JUEB, orv

PATENT OFFICE.

HOPEWELL, VIRGINIA, 'ASSIGNORS TO TUBIZE ARTIFICIAL SILK COMPANY OFAMERICA, A CORPORATION OF DELAWARE.

PROCESS FOR MANUFACTURE OF ARTIFICIAL SILK AND OTHER PRODUCTS FBOICELLULOSE 7 No Drawing.

To all whom it concern.

Be it known that we, EMILE BINDSCHED- ran, a citizen of the Republic ofSwitzerland, and resident of Philadelphia in the county of Philadel hia,in the state of Pennsylvania, and some JUER, recently a subject of theformer Austro-Hungarian Empire, and now a resident of Hopewell, in

' the county of Prince George, in the State of Virginia, haveinventedcertain new and useful Improvements in Processes for the-Manufacture of Artificial Silk and Other Products from CelluloseEsters, of which the following is'a true and exact description. Ourinvention relates to the manufacture of articles from cellulose estersand, particularly, to the manufacture of artificial silk therefrom. Itis known that acetone and its homologues are solvents for celluloseesters but agood practical recess for converting the collodionma e bydissolving cellulose, esters in'acetone orits'homologues intoa clearunclouded product with economical cost of manufacture and recovery ofthe solvents has not heretofore been provided. The object of ourinvention is to provide such a process.

Our invention consists in the process of forming clear unclouded andlustrous products, particularly artificial silk, from cellulose estersby dissolving cellulose esters in acetone or its well'lmown homologuesor" mixtures thereof, imparting to the collodion thus formed the desiredform, as by forcing it through spinnerets to form artificialsilk.filame'ntsand extracting the solvents from the formed filaments orother.

Liquids; well adapted for theremoval cf the acetohe by our process are-certain acids, such as dilute sulphuric acid,solution of. acid salts,suchas 'ni-trecake,or

ments are.

Application fled Iebruary 24, 1922. Serial in. 338,947.

a concentrated solution of calcium chloride.

-Such vsolutions mix readily with the acetone and are entirely withoutefiect upon the cellulose esters, and from all such liquids the acetonecan be readily recovered for reuse by heating the liquids and drivingofi the acetone. Calcium chloride is especially well adapted for use inremoving the acetone because it is both very effective and very cheap. Y

A typical cellulose ester which we have in mind is acetylcellulose andour process is also applicable to the treatment of mixtures of suchcellulose esters and nitrocellulose.

Our process can be carried out not only by the use of acetone and itshomologuesas solvents but also with such solvents used n admixture withothersolvents such, for instance, as ethylalcohol. Such a mixture ofacetone and alcohol can be obtained at,

low cost by the fermentation of corn in a known manner and by reason ofsuch cheapness we prefer to use such a mixture.

In our pending application, Serial No.

425,049 filed'November 17, 1920, we have described andclaimed a processof securing clear unclouded filaments from a collodion formed bydissolving nitroeellulosein acetone or its homologues and extractingthesolvent in a similar way to that above described and in view of saidformer application present claims are to a process or the treatment ofacetylcellulose as distinguished from'nitrocellulose.

While, as we have above stated, the claims of this application arelimited to the use of our described process in the treatment of.acetylcellulose or its homologues, we wish to be clearly understood asintending to cover our prom as applied to niixtures ofsuch celluloseesters and nitrocellulose and a fibre or other product made from acollodion ,formed from such; a mixture has certainjvaluable qualitiesWhere our process 1s applied to mixtures of acetylcellulose esters andnitrocellulose and an "artificial silk fibre is produced from thecollodion .the product must be denitrated by known methods as used withfibre made from nitrocellulose.

.Having now described our invention,

what we claim as new and desire to secure by Letters Patent, is: I i

1. The method of manufacturing clear,

unclouded products from acetylcellulose or e its homologues whichconsists in dissolving the cellulose esters in a solvent made up inwhole er in part of acetone or its homo- .logues, imparting to theacetone-collodion thus formed the desired form and extracting thesolvent by immersing the formed product in a concentrated solution ofcalcium chloride.

2. The method of manufacturing clear, unclouded silk filaments fromacetylcellulose or its homologues which consists in dissolving thecellulose esters in a solvent made up in whole or in part of acetone orits homologues, imparting to the acetone-collodion thus formed thedesired form and extracting the solvent by immersing the formed productin a concentrated solution of calcium chloride.

3. The method of manufacturing clear,

' unclouded silk filaments from acetylcellulose or its homologues whichconsists in dis- .solving the said cellulose esters in a mixture ofacetone and ethylalcohol imparting to the acetone-collodion thus formedthe desired form and extracting the solvent by immersing the formedproduct in a concentrated solution of calcium chloride.

4. The method of manufacturing clear,

' unclouded products from acetylcellulose or its homologues in admixturewith nitrocellulose which consists in dissolving the v said celluloseesters and'nitrocellulose in a solvent made up in whole or part ofacetone orits homologues, imparting to the acetone-collodion thus formedthe desired ture of acetoneand ethylalcohol imparting to theacetone-collodion thus formed de sired form and extracting the solventby immersing the formed productin a concen trated solution of'calciumchloride.

6. The method of manufacturing clear, unclouded silk filaments fromacetone cellulose or its homologues in admixture with nitrocellulosewhich consists in dissolving the cellulose esters and nitrocellulose ina solvent made up in whole or in part of acetone or its homologues,imparting to the acetone-collodion thus formed the desired form andextracting the solvent by immersing the formed product in a concentratedsolution of calcium chloride.

'7. The method of manufacturing clear, unclouded silk filaments fromacetylcellulose or its homologues in admixture with nitrocellulose whichconsists in dissolving the cellulose esters and nitrocellulose in amixture of acetone and ethylalcohol, 'imparting to the acetone-collodionthus formed the desired form and extracting the solvent by immersing theformed product in a concentrated solution of calcium chloride.

8. The method of manufacturing clear, unclouded silk filaments fromacetylcellulose or its homologues in admixture with nitrocellulose whichconsists in dissolving the cellulose esters and nitrocellulose in asolvent made up in whole or in part of acetone .or its homologues,imparting to the acetone-.collodion thus formed the desired form,extracting the solvent by immersing the formed product in a concentratedsolution of calcium chloride and denitrating the produced filament.

, 9. The method of manufacturing clear,

unclouded silk filaments from acetylcellulose or its homologues inadmixture with nitrocellulose which consists in dissolving the saidcellulose esters and nitrocellulose in a mixture of acetone andethylalcohol, imparting to the acetone-collodion thus formed the desiredform and extracting the solvent by immersing the formed product in aconcentrated solution of calcium chloride and denitrating theproduced'filaments.

' EEBINDSCHEDLER.

GEORGE J UER.

